Robert Piepenburg, potter and author of books like Raku Pottery, The Spirit of Clay, Treasures of the Creative Spirit, and The Spirit of Ceramic Design: Cultivating Creativity With Clay, as well as star of several videos is also the inventor of a tool he calls the Piepenburg Trimming Disc. The Trimming Disc is a perfectly designed tool with indestructible working parts. The center of the top disc contains a slight dip to assure the positioning of the fingertip. The underside of the bottom disc contains radial ribs to grip soft clay and prevent it from sliding off-center. The press-fitted thrust bearing sandwiched between them allows for a silent smooth rotation. Its yellow coloring makes it easy to locate in the studio and puts a little "sunshine" in the toolbox. Includes a 10-minute instructional DVD (worth the cost of the tool itself!) with tips on trimming from Robert Piepenburg.